- Atherosclerosis on standard carotis duplex ultrasound: Carotid standard ultrasound will be performed using a Philips (Bothel, WA) iU22 ultrasound scanner equipped with a linear array L9-3 MHz probe. The examinations will be performed by a trained vascular specialist using a standard imaging protocol. Both left and right carotid arteries will be examined. The examination includes B-mode ultrasound imaging, color Doppler ultrasound and pulsed Doppler spectral analysis of the common carotid artery (CCA), the extracranial segments of the internal carotid artery (ICA), and the external carotid artery. The mean and maximal IMT value will be measured at the distal part of CCA (2 cm proximal of the tip of the flow divider) at the fare wall using an automated edge detection program (QLAB software, Philips; Bothel, WA). The degree of stenosis of the ICA at both sides will be graded according to current guidelines as 30-50%, 50-69%, or ≥ 70% stenosis based on spectral Doppler velocities. The lesion area [cm2] of each plaque will be calculated by drawing a region of interest along the lumen-intima interface and the media-adventitia interface of each plaque in a 2D longitudinal plan. Total lesion burden will be expressed as total plaque area and will be calculated by adding all plaques areas of both sides. Total lesion volume [cm3] of each carotid plaque will be measured using stacked contours measurements from 3D data using a General Imaging 3D Quantification program (QLAB software, Philips). Lesion echogenicity of each plaque will be classified according to well established criteria as uniformly echolucent (Class I), predominantly echolucent (Class II), predominantly echogenic (Class III), uniformly echogenic or extensively calcified (Class IV).